The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. However, these advances have increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed. In the course of integrated circuit evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased.
The ever-shrinking geometry size brings challenges to semiconductor fabrication. For example, misalignment between microelectronic components (such as misalignment between a source/drain and a conductive contact formed thereover) during fabrication may occur, which may damage the semiconductor device or degrade its performance. In addition, the smaller device sizes may lead to more significant parasitic capacitance, which could also negatively affect semiconductor device performance.
Therefore, while existing semiconductor devices and the fabrication thereof have been generally adequate for their intended purposes, they have not been entirely satisfactory in every aspect.